It’s Always Sunny in Philadelphia — Live!

The Nightman Cometh — a live adaptation of a musical episode of cult FX comedy It’s Always Sunny in Philadelphia — cameth to the Beacon Theatre last night, on the second night of its short theatrical run. For the uninitiated, Sunny revolves around the various plots of a gang of selfish, deluded, remarkably productive jerks who run a dive bar in Philly; in the “Nightman Cometh” episode, Charlie (Charlie Day), the shrillest, funniest character, writes and produces a musical in an attempt to woo his unrequited love, a waitress in a coffee shop.

The actual stage production didn’t veer from the fictional (and confusing, and crappy) musical: a young boy, enslaved by a troll and in love with a princess who works in a coffee shop, mans up and kills the troll as well as the evil molester Nightman, to become the heroic Day Man, thereby winning his girl’s affection.

Sunny is one of the few shows for which a live adaptation could happen: Despite entering its fifth season (tonight! On FX! 10/9 p.m. Central!), its cast isn’t famous enough (save maybe for Danny DeVito) to worry about embarrassing themselves with a risky idea; meanwhile, its niche audience is obsessed enough to sell the performance out in a day.

As we expected, the whole cast was rapturously received, although special attention was reserved for Rob McElhenney (as Mac as Nightman), who has the eyes of a cat and does karate moves as he saunters across the stage. Elsewhere, Charlie tossing DeVito as Frank as the Troll’s chewed gum out into the audience got a nice collective screech, and a conversation in which Charlie chastises Glenn Howerton (as Dennis as a young boy) for eating too many baby Snickers was funny enough to crack Howerton himself up.

Nightman Cometh would have worked better in a smaller space, where the muffed lines would have been more easily forgiven and the awkward headset mikes (turned up way too loud) wouldn’t have been necessary, but by the time of the big, satisfying closing number, “Day Man,” nobody seemed to mind.

It was all about the crowd-pleasing, anyway: Later, at the after-party at the Empire Hotel, a typical Sunny obsessive (young, male, unshaven) asked Mac to take a picture with him while striking a karate pose. “You didn’t get enough fucking karate in the show?” Mac replied — but chopped down on the fan’s neck anyway.